The ability to store and retrieve data and other information in an efficient manner has become an extremely important factor in everyday life. The use of computers for example, in both commercial and non-commercial environments has become commonplace. Both magnetic disk drives and magnetic tapes have been used to provide mass storage for applications with large programs or large amounts of data. Video displays of various types, often connected to computers, have also used prestored information.
Magnetic memories, especially in the form of magnetic tape, have been used to store video signals for subsequent replay. The most common form of such memories is used in commercially available video cassette recorders. Such video tapes can be recorded on and replayed many times. However, the playback equipment is electromechanical and of necessity is rather bulky.
An alternate form of a prerecorded video playback memory is the so-called video disk wherein video signals are prerecorded onto a rotatable disk. The commercially available disks are replayed by rotating the disk and sensing the prerecorded video much like a traditional record is played. In this instance also the playback mechanism is electromechanical and bulky. Further, no modifications at all can be made in the field to the information prerecorded onto the video disk.
While magnetic memories have been generally successful and have found wide uses, the disks or tapes are fragile and must be handled with extreme care to avoid bending or other physical damage to the same. Any structural irregularity in a disk can render it useless. Also, the disks or tapes have a finite shelf life and should it be desired to maintain the stored information for a substantial period of time, the stored information should be periodically transferred to a new disk. Further, these disks or tapes can only be read by equipment which is rather complex, with read heads which are fragile, which often require periodic cleaning and service, and which is bulky and not readily portable.
There is thus a need in the art for a video playback system that is electronic as opposed to electro-mechanical in nature and which can take advantage of recent developments in high density, large capacity solid state memories that do not require moving parts. The system should also use interpolation techniques where possible so as to maximize the length of the display for a given memory size.